Copolymer Synthesis Process

ABSTRACT

Preparing a non-ionic copolymer having a hydrolysable monomer residue and a polyether macromonomer residue in a semicontinuous mode in a polymerization reactor associated with a metering device, including introducing polyether macromonomer and water into the reactor, wherein hydrolysable monomer which is added thereto forms a polymerization reaction mixture; introducing hydrolysable monomer into the metering device; adding hydrolysable monomer into the reactor from the metering device; passing a free radical polymerization initiator into the reactor before and/or during the addition of the hydrolysable monomer, the hydrolysable monomer and the polyether macromonomer reacting by free radical polymerization to form the non-ionic copolymer; and, subjecting the reaction mixture to polymerization while an addition rate of the hydrolysable monomer and/or at least a component of the polymerization initiator is varied stepwise or continuously. No monomer is introduced to incorporate ionic cement binding sites into the non-ionic copolymer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Ser. No. 12.477,565,filed Jun. 3, 2009, which claims the benefit of the filing date, under35 U.S.C. §119(e), from U. S. Provisional Application Ser. No.61/061,821, filed Jun. 16, 2008, which applications are incorporatedherein by reference.

Conventional dispersants for cementitious compositions typically achievegood water reduction, however, they are limited in their ability toretain workability over a long period of time. An alternate method forextended workability retention is the use of retarding admixtures. Inthis scenario, the benefit of workability retention is often achieved atthe expense of setting times and early strength. The usefulness of thesedispersants is therefore limited by their inherent limitations inmolecular architecture.

Conventional dispersants are static in their chemical structure overtime in cementitious systems. Their performance is controlled by monomermolar ratio that is fixed within a polymer molecule. A water reducingeffect or dispersing effect is observed upon dispersant adsorption ontothe cement surface. As dispersant demand increases over time due toabrasion and hydration product formation, which creates more surfacearea, these conventional dispersants are unable to respond andworkability is lost.

Typically, the issue of extended workability is solved by eitherre-tempering (adding more water) to the concrete at the point ofplacement to restore workability, or by adding more high range waterreducer. Addition of water leads to lower strength concrete and thuscreates a need for mixes that are “over-designed” in the way of cementcontent. Site addition of high range water reducer requires truckmounted dispensers which are costly, difficult to maintain, anddifficult to control.

The subject non-ionic copolymers are initially non-dispersing molecules,having low or no affinity to cement particles, and therefore do notcontribute to achieving the cementitious composition's initialworkability targets. The subject copolymers remain in solution, however,acting as a reservoir of potential dispersant polymer for future use.Over time, as dispersant demand increases, due either in part to theexhaustion of conventional dispersant as discussed above, or partly orwholly to mix design factors, these molecules undergo base-promotedhydrolysis reactions along the polymer backbone which generate activebinding sites both to initialize and to increase the polymer's bindingaffinity, resulting in the in-situ generation of “active” dispersantpolymer over time, to extend slump and workability of the composition.

The use of the subject non-ionic copolymers as a potential dispersantreservoir in cementitious compositions provides extended workabilityretention beyond what has previously been achievable with staticpolymers. Use of the subject non-ionic copolymers alleviates the need tore-temper, and allow producers to reduce cement content (and thus cost)in their mix designs. Use of the subject non-ionic copolymers allows forbetter control over longer-term concrete workability, more uniformityand tighter quality control for concrete producers.

Provided is a process for extending workability to a cementitiousmixture containing hydraulic cement and water, comprising introducinginto the cementitious mixture an admixture comprising a substantiallynon-ionic copolymer. In one embodiment, the process introduces anon-ionic, polyether-polyester copolymer into the cementitious mixture.The subject process achieves slump retention and also the production ofhigh early strength cementitious compositions.

Also provided are novel non-ionic copolymers comprising a hydrolysablemoiety and at least one dispersing moiety, and a process for theirsynthesis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graphical representation of concrete slump versus timeachieved by the use of a subject copolymer as compared to conventionalpolycarboxylate dispersants and no slump-affecting admixture.

FIG. 2 is a graphical representation of concrete slump versus timeachieved by the use of a subject copolymer as compared to conventionalpolycarboxylate dispersants and no slump-affecting admixture.

FIG. 3 is a graphical representation of concrete slump versus timeachieved by the use of a subject copolymer as compared to conventionalpolycarboxylate dispersants and no slump-affecting admixture.

FIG. 4 is a graphical representation of the adsorption of variousembodiments of the subject copolymer onto cement particles versus timeas compared to a conventional polycarboxylate dispersant.

FIG. 5 is a graphical representation of hydrolyzation of subjectcopolymers versus time comparing two embodiments of the subjectcopolymer.

FIG. 6 is a graphical representation of concrete slump versus timeachieved by the use of various dosages of one embodiment of a subjectcopolymer in combination with a conventional water reducing dispersantas compared to a conventional water reducing dispersant.

FIG. 7 is a graphical representation of concrete slump versus timeachieved by the use of various embodiments of the subject copolymer incombination with a conventional naphthalene sulfonate dispersant ascompared to a conventional naphthalene sulfonate dispersant.

FIG. 8 is a graphical representation of concrete slump versus timeachieved by the use of various embodiments of a subject copolymer incombination with a conventional polycarboxylate dispersant versus aconventional polycarboxylate dispersant.

FIG. 9 is a graphical representation of concrete slump versus timeachieved by the use of various dosages of one embodiment of a subjectcopolymer in combination with a conventional polycarboxylate dispersantversus a conventional polycarboxylate dispersant.

FIG. 10 is a graphical representation of concrete slump versus timeachieved by the use of various embodiments of subject copolymerscomprising both Component B and Component C in combination with aconventional polycarboxylate dispersant versus a conventionalpolycarboxylate dispersant.

DETAILED DESCRIPTION

A process is provided for extending workability to a cementitiousmixture containing hydraulic cement and water, comprising introducinginto the cementitious mixture an admixture comprising a substantiallynon-ionic copolymer, wherein the copolymer comprises residues of atleast the following monomers:

Component A comprising at least one ethylenically unsaturated carboxylicacid ester monomer comprising a moiety hydrolysable in the cementitiousmixture, wherein the hydrolyzed monomer residue comprises an activebinding site for a component of the cementitious mixture; and,

at least one of:

-   -   Component B comprising at least one ethylenically unsaturated,        carboxylic acid ester or alkenyl ether monomer comprising at        least one C₂₋₄ oxyalkylene side group of about 1 to 30 units;        or,    -   Component C comprising at least one ethylenically unsaturated,        carboxylic acid ester or alkenyl ether monomer comprising at        least one C₂₋₄ oxyalkylene side group of 31 to about 350 units;

wherein the molar ratio of Component A to the sum of the molar ratios ofComponent B and Component C is about 1:1 to about 10:1. In certainembodiments, both Component B and Component C are present in the subjectcopolymer.

A novel, substantially non-ionic polyether-polyester copolymer isprovided for extending workability to a cementitious mixture containinghydraulic cement and water, wherein the copolymer comprises residues ofat least the following monomers:

Component A comprising at least one ethylenically unsaturated carboxylicacid ester monomer comprising a moiety hydrolysable in the cementitiousmixture, wherein the hydrolyzed monomer residue comprises an activebinding site for a component of the cementitious mixture; and,

at least one of:

-   -   Component B comprising at least one ethylenically unsaturated,        carboxylic acid ester or alkenyl ether monomer comprising at        least one C₂₋₄ oxyalkylene side group of about 1 to 30 units;        or,    -   Component C comprising at least one ethylenically unsaturated,        carboxylic acid ester or alkenyl ether monomer comprising at        least one C₂₋₄ oxyalkylene side group of 31 to about 350 units;

wherein the molar ratio of Component A to the sum of the molar ratios ofComponent B and Component C is about 1:1 to about 10:1. In certainembodiments, both Component B and Component C are present.

Also provided is a cementitious composition comprising hydraulic cement,water, and an admixture comprising the non-ionic polyether-polyestercopolymer set forth above.

A process is provided for the preparation of a non-ionic copolymercomprising at least one hydrolysable monomer residue and at least onepolyether macromonomer residue in a semicontinuous mode of operation ina polymerization apparatus containing a polymerization reactorassociated with, or connected to, a metering device, the processcomprising:

introducing at least a portion of the polyether macromonomer with lowreactivity (relative to the hydrolysable monomer) and water into thepolymerization reactor, wherein the hydrolysable monomer with higherreactivity which is added thereto forms an aqueous medium polymerizationreaction mixture, optionally wherein the aqueous medium is present inthe form of an aqueous solution;

introducing at least a portion of the hydrolysable monomer into themetering device;

adding at least a portion of the hydrolysable monomer into thepolymerization reactor from the metering device;

passing a free radical polymerization initiator into the polymerizationreactor before and/or during the addition of the hydrolysable monomerinto the polymerization reactor, wherein the hydrolysable monomer andthe polyether macromonomer are reacted in the aqueous mediumpolymerization reaction mixture by free radical polymerization withformation of the non-ionic copolymer; and,

subjecting the reaction mixture to polymerization while an addition rateof the hydrolysable monomer and/or at least a component of the freeradical polymerization initiator is varied stepwise or continuously;

wherein no monomer is introduced into the polymerization reactor toincorporate ionic cement binding sites into the non-ionic copolymerprior to mixing the copolymer in an alkaline aqueous environment(including but not limited to a cementitious composition).

In one embodiment, the subject copolymer admixture system may includevaried portions of a water reducing polymer, used in combination withthe subject copolymer in which the binding sites have been substantiallyprotected to the extent that the copolymer has essentially no dispersingcharacteristics when it is initially dosed. For example, due to theabsence of ionic binding moieties in the copolymer upon dosing, there isessentially no initial dispersing activity. After dosing, orintroduction into the cementitious composition, the deactivated orprotected binding site moieties in the subject copolymers arehydrolyzed, or activated, at an appropriate rate to counter the loss ofdispersion that is expected when the water reducer is used alone. Inother embodiments, the protected binding site moieties may be chosenbased on their hydrolysis rate(s) in order to optimize workability overtime as compared to conventional water reducers.

The use of the subject copolymer admixture system has distinctadvantages over a single component system, in that the concrete producerhas a virtually infinite opportunity to respond to the variety ofconditions that may be experienced in the field. For example, theproducer may not require significantly extended slump retention forshort-haul projects, and therefore the cementitious mix design couldinclude very little of the non-ionic copolymer, instead relying mainlyon a conventional water reducer for workability performance. This mayalso be the case in cold weather conditions. However, in warmerconditions, or for longer haul projects, there would increasingly be theneed for additional amounts of the hydrolysable non-ionic copolymer andpotentially less of the conventional water reducer. The batch-to-batchvariability in cementitious mix performance requirements, and hour tohour variance in temperature, can be accommodated by the copolymeradmixture system for optimal efficiency at ready mix, and to a lesserextent, precast concrete producers.

The hydraulic cement can be a portland cement, a calcium aluminatecement, a magnesium phosphate cement, a magnesium potassium phosphatecement, a calcium sulfoaluminate cement, pozzolanic cement, slag cement,or any other suitable hydraulic binder. Aggregate may be included in thecementitious composition. The aggregate can be silica, quartz, sand,crushed marble, glass spheres, granite, limestone, calcite, feldspar,alluvial sands, any other durable aggregate, and mixtures thereof

The non-ionic copolymers of the subject copolymer admixture system haveall, or substantially all, of their potential cement binding sitesblocked, or protected, with hydrolysable groups that are stable tostorage and formulation conditions, but these latent binding sites aretriggered to be unblocked or de-protected when the copolymer comes intocontact with the highly alkaline chemical environment that is found inconcrete cementitious mixtures. Therefore, the non-ionic copolymers havelittle or no affinity for cementitious particles upon introduction intothe cementitious composition, but develop affinity over time as thehydrolysable groups do hydrolyze.

By way of illustration, but not for limitation, the hydrolysable moietymay comprise at least one of a C₁₋₂₀ alkyl ester, C₁₋₂₀ amino alkylester, C₂₋₂₀ alcohol, C₂₋₂₀ amino alcohol, or amide. Hydrolysablemoieties may include, but are not limited to, acrylate or methacrylateesters of varied groups having rates of hydrolysis that make themsuitable for the time scale of concrete mixing and placement, in certainembodiments up to about 2 to about 4 hours. For example, in oneembodiment the ethylenically unsaturated monomer of Component A mayinclude an acrylic acid ester with an ester functionality comprising thehydrolysable moiety. In certain embodiments, a hydroxyalkanol, such as ahydroxyethanol or hydroxypropylalcohol function comprises the latentbinding sites as the hydrolysable moiety of a carboxylic acid esterresidue. The ester functionality may therefore comprise at least one ofhydroxypropyl or hydroxyethyl. In other embodiments, other types oflatent binding sites with varying rates of saponification are provided,such as acrylamide or methacrylamide derivatives. In certainembodiments, the ethylenically unsaturated monomer of Component A maycomprise an imide, optionally comprising maleimide.

Of course, the subject copolymer may comprise the residues of more thanone Component A ethylenically unsaturated monomer comprising ahydrolysable moiety. For example, more than one Component Aethylenically unsaturated monomer comprising a hydrolysable moiety mayinclude the residues of a) more than one type of ethylenicallyunsaturated monomer; b) more than one hydrolysable moiety; or c) acombination of more than one type of ethylenically unsaturated monomerand more than one hydrolysable moiety. By way of illustration, but notfor limitation, the hydrolysable moiety may comprise at least one ormore than one C₂₋₂₀ alcohol functionality.

Selection of either or both of the type of ethylenically unsaturatedmonomer residue unit incorporated into the copolymer chain, and thehydrolysable moiety derivative, or hydrolysable side group, linked tothe residue, as well as the type of linkage, affects the rate ofhydrolysis of the latent binding site in use, and thus the duration ofworkability of the cementitious composition comprising the non-ioniccopolymer.

Side chain containing groups of Component B and Component C monomers maycomprise C₂ to C₄ oxyalkylene chains of varying length, that is, varyingnumber of oxyalkylene units such as either (poly)ethylene oxide,(poly)propylene oxide, or combinations thereof, and may include linkagessuch as esters or ethers. In certain embodiments, a portion of the sidechains have a relatively shorter length (lower molecular weight)contributing to improved mass efficiency, and a portion of the sidechains have a relatively longer length (higher molecular weight)contributing to a higher dispersing effect when the latent binding siteshydrolyze and become available for binding to the cementitiousparticles.

In certain embodiments, one or more of the Component B and/or one ormore of the Component C monomers may be non-hydrolysable in cementitiouscompositions. In certain embodiments of the subject non-ionic copolymer,at least one of the Component B or Component C ethylenically unsaturatedmonomers may comprise a non-hydrolysable C₂₋₈ carboxylic acid ester. Incertain other embodiments, the at least one of the Component B orComponent C ethylenically unsaturated monomers may additionally oralternatively comprise a C₂₋₈ alkenyl group, optionally anon-hydrolysable C₂₋₈ alkenyl ether group.

In the latter embodiments, the non-hydrolysable ethylenicallyunsaturated monomer may comprise a vinyl, allyl or (meth)allyl ether, ormay be derived from a C₂₋₈ unsaturated alcohol. By way of illustrationbut not limitation, the C₂₋₈ unsaturated alcohol may be at least one ofvinyl alcohol, (meth)allyl alcohol, isoprenol, or anothermethyl-butenol.

In other embodiments, at least one of the Component B or Component Cethylenically unsaturated monomers may comprise a (meth)acrylic acidester.

The oxyalkylene side group of the Component B and/or Component Cethylenically unsaturated monomers may comprises at least one ofethylene oxide, propylene oxide, polyethylene oxide, polypropyleneoxide, or mixtures thereof. The oxyalkylene units may be present in theform of homopolymers, or random or block copolymers. Depending upon themonomers from which the copolymer is synthesized, at least one of theComponent B or Component C ethylenically unsaturated monomer side groupsmay contain at least one C₄ oxyalkylene unit.

In certain embodiments, the non-ionic copolymer may comprise additionalnon-ionic, non-hydrolysable Component D monomer residues derived fromother non-hydrolysable ethylenically unsaturated monomers, such as butnot limited to styrene, ethylene, propylene, isobutene, alpha-methylstyrene, methyl vinyl ether, and the like.

In certain embodiments, the mole ratio of Component A to Components Band C, that is, (A):(B+C), is between about 1:1 to about 10:1, incertain embodiments about 1:1 to about 9:1. In certain embodiments,where both Component B and Component C are present in the copolymer, themole ratio of (B):(C) is between about 0.7:0.3 to about 0.3:0.7. Inother embodiments, the mole ratio of (B):(C) is between about 0.95:0.05to about 0.05:0.95.

In certain embodiments, the non-ionic copolymer is represented by thefollowing general formula (I):

wherein Q is a Component A ethylenically unsaturated monomer comprisinga hydrolysable moiety; G comprises O, C(O)—O, or O—(CH₂)_(p)—O where p=2to 8, and wherein mixtures of G are possible in the same polymermolecule; R¹ and R² each independently comprise at least one C₂-C₈alkyl; R³ comprises (CH₂)_(c) wherein each c is a numeral from 2 toabout 5 and wherein mixtures of R³ are possible in the same polymermolecule; each R⁵ comprises at least one of H, a C₁₋₂₀ (linear orbranched, saturated or unsaturated) aliphatic hydrocarbon radical, aC₅₋₈ cycloaliphatic hydrocarbon radical, or a substituted orunsubstituted C₆₋₁₄ aryl radical; m=1 to 30, n=31 to about 350, w=about1 to about 10, y=0 to about 1, and z=0 to about 1; and wherein y+z isgreater than 0 to about 1 and w is less than or equal to 10 times thesum of y+z. Examples of the ethylenically unsaturated monomer comprisinga hydrolysable moiety are discussed above.

In particular embodiments, the non-ionic copolymer is represented by thefollowing general formula (II):

wherein G comprises O, C(O)—O, or O—(CH₂)_(p)—O where p=2 to 8, andwherein mixtures of G are possible in the same polymer molecule; Rcomprises at least one of H or CH₃; R¹ and R² each independentlycomprise at least one C₂-C₈ alkyl; R³ comprises (CH₂)_(c) wherein each cis a numeral from 2 to about 5 and wherein mixtures of R³ are possiblein the same polymer molecule; X comprises a hydrolysable moiety; each R⁵comprises at least one of H, a C₁₋₂₀ (linear or branched, saturated orunsaturated) aliphatic hydrocarbon radical, a C₅₋₈ cycloaliphatichydrocarbon radical, or a substituted or unsubstituted C₆₋₁₄ arylradical; m=1 to 30, n=31 to about 350, w=about 1 to about 10, y=0 toabout 1, and z=0 to about 1; and wherein y+z is greater than 0 to about1 and w is less than or equal to 10 times the sum of y+z. According tothis formula, in certain embodiments, the hydrolysable moiety maycomprise at least one of alkyl ester, amino alkyl ester, hydroxyalkylester, amino hydroxyalkyl ester, or amide such as acrylamide,methacrylamide, and their derivatives.

In specific embodiments, the non-ionic copolymer is represented by thefollowing general formula (III):

wherein G comprises O, C(O)—O, or O—(CH₂)_(p)—O where p=2 to 8, andwherein mixtures of G are possible in the same polymer molecule; Rcomprises at least one of H or CH₃; R¹ and R² each independentlycomprise at least one C₂-C₈ alkyl; R³ comprises (CH₂)_(c) wherein each cis a numeral from 2 to about 5 and wherein mixtures of R³ are possiblein the same polymer molecule; R⁴ comprises at least one of C₁₋₂₀ alkylor C₂₋₂₀ hydroxyalkyl; each R⁵ comprises at least one of H, a C₁₋₂₀(linear or branched, saturated or unsaturated) aliphatic hydrocarbonradical, a C₅₋₈ cycloaliphatic hydrocarbon radical, or a substituted orunsubstituted C₆₋₁₄ aryl radical; m=1 to 30, n=31 to about 350, w=about1 to about 10, y=0 to about 1, and z=0 to about 1; and wherein y+z isgreater than 0 to about 1 and w is less than or equal to 10 times thesum of y+z. According to this formula, in certain embodiments, anon-ionic copolymer may be used wherein each p is 4; each R⁴ comprisesC₂H₄OH or C₃H₆OH; each R⁵ comprises H; m=about 5 to 30, n=31 to about250, w=about 1 to about 9, y=0 to about 1, and z=0 to about 1; andwherein y+z is greater than 0 to about 1, and w is less than or equal to9 times the sum of y+z.

With reference to formulas (I), (II) and (III), in certain embodimentsthe molar ratio of w to (y +z) may be about 1:1 to about 10:1. Also withreference to formulas (I), (II) and (III), in certain embodiments themolar ratio of w to (y+z) may be about 1:1 to about 9:1.

The subject non-ionic copolymers can be prepared by combining theirrespective substituted component monomers and initiatingco-polymerization, or by the following polymerization techniques.

The non-ionic copolymer may be prepared by batch, semi-batch,semi-continuous or continuous procedures, including introduction ofcomponents during initiation of polymerization, by linear dosagetechniques, or by ramp-wise dosage techniques with changes in dosagestepwise or continuously, both to higher and/or lower dosage rates incomparison to the previous rate.

A process is provided for the preparation of a non-ionic copolymercomprising at least one hydrolysable monomer residue and at least onepolyether macromonomer residue in a semicontinuous mode of operation ina polymerization apparatus containing a polymerization reactorassociated with, or connected to, a metering device, the processcomprising:

introducing at least a portion of the polyether macromonomer with lowreactivity (relative to the hydrolysable monomer) and water into thepolymerization reactor, wherein the hydrolysable monomer with higherreactivity which is added thereto forms an aqueous medium polymerizationreaction mixture, optionally wherein the aqueous medium is present inthe form of an aqueous solution;

introducing at least a portion of the hydrolysable monomer into themetering device;

adding at least a portion of the hydrolysable monomer into thepolymerization reactor from the metering device;

passing a free radical polymerization initiator into the polymerizationreactor before and/or during the addition of the hydrolysable monomerinto the polymerization reactor, wherein the hydrolysable monomer andthe polyether macromonomer are reacted in the aqueous mediumpolymerization reaction mixture by free radical polymerization withformation of the non-ionic copolymer; and,

subjecting the reaction mixture to polymerization while an addition rateof the hydrolysable monomer and/or at least a component of the freeradical polymerization initiator is varied stepwise or continuously;

wherein no monomer is introduced into the polymerization reactor toincorporate ionic cement binding sites into the non-ionic copolymerprior to mixing the copolymer in an alkaline aqueous environment(including but not limited to a cementitious composition).

In certain embodiments, at least 70 mol % of the polyether macromonomerinitially introduced into the polymerization reactor is converted byfree radical polymerization.

The hydrolysable monomers include monomers that are capable of freeradical polymerization, having at least one carbon double bond. In thepresent context, polyether macromonomers are compounds capable of freeradical polymerization and having at least one carbon double bond and atleast two ether oxygen atoms. In certain embodiments, the polyethermacromonomer moieties present in the copolymer have side chains thatcontain at least two ether oxygen atoms.

It is not necessary, although it is possible, initially to introduce allpolyether macromonomer reacted by free radical polymerization in thepolymerization reactor into the polymerization reactor before thehydrolysable monomer is metered in. However, in certain embodiments atleast 50 mol %, in other embodiments at least 80 mol %, and in manyother embodiments about 100% of the polyether macromonomer moieties areincorporated into the copolymer by reaction of polyether macromonomerwhich is initially introduced into the polymerization reactor before thehydrolysable monomer is metered in. The polyether macromonomer thenoptionally remaining may be fed continuously to the polymerizationreactor while the hydrolysable monomer is being metered in. Polyethermacromonomer can be fed to the polymerization reactor separately fromthe hydrolysable monomer and/or as a mixture with the hydrolysablemonomer (by, for example, also initially introducing polyethermacromonomer in addition to the hydrolysable monomer into the meteringdevice). The metering device may have various forms and can be manuallyand/or automatically controlled.

According to this synthesis process, including selective metering, it ispossible to prepare uniform copolymers, and to do so with respect tomolecular weight (low polydispersity index of the molecular weightdistribution) and with regard to the relative proportion of the monomermoieties in the copolymer (chemical uniformity). This uniformity of thenon-ionic copolymer results in the same being particularly suitable as aworkability retention admixture for hydraulic binders. The process canalso be regarded as being economical, as a good effect is achieved withonly little metering effort, resulting from “high metering efficiency”.

It is therefore possible to achieve a more homogeneous distribution ofthe monomer residues in the copolymer for the sake of better performancewith respect to workability as measured by slump retention once thecopolymers are introduced into the cementitious composition andsubsequently hydrolyze.

In addition to the hydrolysable monomer and the polyether macromonomer,further monomer types may also be used. In certain embodiments, thesemay be reacted so that in practice a vinylically or ethylenicallyunsaturated compound is passed into the polymerization reactor asmonomeric starting material, which compound is reacted bypolymerization.

In one embodiment, polyether macromonomer is initially introduced intothe polymerization reactor in an amount per mole of hydrolysable monomerto be metered in, such that an arithmetic mean molar ratio ofhydrolysable monomer residues to polyether macromonomer residues of 10:1to 1:1, and in other embodiments a molar ratio of 9:1 to 1:1, isestablished in the copolymer formed.

In certain embodiments, a redox initiator or redox initiator system isused as the free radical polymerization initiator. The H₂O₂/FeSO₄combination may be used as the redox initiator system, in certainembodiments together with a reducing agent. Sodium sulphite, thedisodium salt of 2-hydroxy-2-sulphinatoacetic acid, disodium salt of2-hydroxy-2-sulphonatoacetic acid, sodium hydroxymethanesulphinate,ascorbic acid, isoascorbic acid or mixtures thereof are suitable asreducing agents within the redox initiator system. Other systems arealso suitable as the redox initiator system, for example those which arebased on tert-butyl hydroperoxide, ammonium peroxodisulphate orpotassium peroxodisulphate.

In one embodiment, initiator components, e.g. H₂O₂, and the polyethermacromonomer are passed simultaneously in premixed form (such as in onestream) into the polymerization reactor.

In principle, however, all compounds decomposing into free radicalsunder polymerization conditions can be used as initiators, such as, forexample, peroxides, hydroperoxides, persulphates, azo compounds andperphosphates. When the free radical formers are combined with suitablereducing agents, known redox systems or redox catalysts are obtained.Suitable reducing agents are, for example, sodium sulphite, the disodiumsalt of 2-hydroxy-2-sulphonatoacetic acid, the disodium salt of2-hydroxy-2-sulphinatoacetic acid, sodium hydroxymethanesulphinate,ascorbic acid, iso-ascorbic acid, amines, such as diethanolamine ortriethanolamine, hydroxylamine or mixtures thereof. In some embodiments,water-soluble salts of transition metals, such as iron, cobalt, nickelor silver, may be additionally employed with the use of redox systems orcatalysts, and in certain embodiments, iron salts (present predominantlyin divalent form) may be used.

In general, a component of the redox initiator system and/or reducingagent may be passed into the polymerization reactor after thepolymerization pH has been established, and during the metering in ofthe hydrolysable monomer.

The polymerization pH in the aqueous medium may be established so that,with regard to the free radical polymerization initiator used, the freeradical formation per unit time (free radical yield) is high orapproximately at a maximum. The polymerization initiator or thepolymerization initiator system used, thus influences and helps toapproximately determine the polymerization pH.

Typically, the aqueous medium is in the form of an aqueous solution. Thepolymerization pH may be about 4.5 to about 7.1, and the temperature ofthe aqueous medium during the free radical polymerization is 0 to about90° C., in certain embodiments about 10 to 35° C. The desiredpolymerization pH in the aqueous medium in the reactor may beestablished by adding a base or an acid to the polymerization reactorand/or to the metering device.

The polymerization reactor may comprise a semicontinuously stirred tank.

In certain embodiments, at least 80 mol % to at least 90 mol %, of thepolyether macromonomer initially introduced into the polymerizationreactor is converted by the free radical polymerization.

Generally, at least 70 mol % of the polyether macromonomer having beeninitially introduced into the polymerization reactor, the hydrolysablemonomer is added into the polymerization reactor in an amount per unittime such that the uniformity of the mole ratio of the constituentmonomer residues in the copolymer chains is controlled.

In some embodiments, the hydrolysable monomer is initially introducedtogether with water into the metering unit, and an aqueous solution ofthe hydrolysable monomer is metered from the metering unit into thepolymerization reactor. In general, a chain regulator, or chain transferagent, which may be present in dissolved form, is passed into thepolymerization reactor. The process may therefore include passing achain transfer agent into the polymerization reactor, before and/orduring the addition of the hydrolysable monomer into the polymerizationreactor.

Suitable chain transfer agents include, among others, thiol typecompounds such as but not limited to mercaptoethanol, thioglycerol,thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid,thiomalic acid, octylthioglycolic acid, octyl 3-mercaptopropionic acid,and 2-mercaptoethanesulfonic acid. Chain transfer agents may be usedeither singly or in the form of a mixture of two or more. In certainembodiments, the chain transfer agent is present as a water solublecompound and is passed into the polymerization reactor in the form of anaqueous solution. The aqueous solution may contain at least 10% byweight of water.

When ether-based monomer(s), such as polyether macromonomer(s), is usedas Component B and/or Component C, and there is a reactivity differencebetween those monomers and the hydrolysable monomers of Component A suchthat the self-polymerizability (homopolymerizability) of Components B orC is lower and the homopolymerizability of Component A is higher, thenComponent B and/or Component C may be difficult to be continuouslyincorporated in a copolymer and either the added Component A ispreferentially polymerized, or only the Component A is polymerized, witha resulting decrease of reaction rate of Component B and/or Component C.

A process is therefore provided for producing a non-ionic copolymer bypolymerizing polyether macromonomer and hydrolysable monomer, comprisingadding at least a portion of the polyether macromonomer with lowreactivity into a reactor in advance and subsequently adding thereto ahydrolysable monomer with higher reactivity to form a polymerizationreaction mixture, and subjecting the reaction mixture to polymerizationwhile an addition rate of the hydrolysable monomer with high reactivity,and/or at least a component of the free radical polymerization initiatorsuch as a reducing agent for a redox initiator system, is variedstepwise or continuously, with either increasing and/or decreasingaddition rates.

As a result, a copolymer with more uniform monomer composition, lowerpolydispersity index (PDI), or a blend of a plurality of copolymers withdifferent monomer ratios can easily be produced by one polymerizationoperation by making the addition rate at the later stage faster orlower. For example, when the addition rate of the hydrolysable monomerComponent A is made slower at the later step, a copolymer with moreuniform monomer molar ratio in a mixture can be produced.

In one embodiment, at least one ethylenically unsaturatedpolyoxyalkylene ether-based monomer (Component B and/or C) is added intoa reactor in advance, and at least one ethylenically unsaturatedhydrolysable monomer (Component A) is added thereto with an additionrate that changes at least one time.

Each of the monomers of Component A and Components B and/or C may beused alone or in a mixture of two or more monomers. In addition to themonomers of Components A, B and C, further unsaturated monomers ofComponent D may be used, either alone or in a mixture of two or moremonomers.

The ethylenically unsaturated monomer(s) of Components B and/or C may beinitially added in advance into a reactor in their whole amount beforestarting the copolymerization with the ethylenically unsaturated monomerof Component A, in one embodiment before the addition of any of themonomer(s) of Component A, and in other embodiments before the additionof the monomer(s) of Component A and the polymerization initiator.However the polymerization reaction mixture may contain a portion of themonomers of Components B and/or C together with Component A beforepolymerization is commenced, and portion of the monomers of Components Band/or C may be co-fed with the monomer(s) of Component A during thestepwise addition.

The number of times to change the addition rate of the monomer(s) ofComponent A is not limited and can be properly selected depending on thedesired characteristics of the non-ionic copolymer to be produced. Whenthe addition rate of the monomer(s) of Components B and/or C is changedstepwise in the present method, the addition of the monomer(s) in anystep in which the monomer is added at a constant rate, may itself beperformed continuously, semicontinuously, and/or stepwise.

Timing of adding the monomer(s) of Component D, when used, is notlimited as long as the timing allows such monomer(s) to copolymerizewith the monomers of Component A and Components B and/or C efficientlyto produce the desired blend of copolymers. By way of example and notlimitation, the monomer(s) of Component D may be added into a reactor inadvance together with the monomer(s) of and Components B and/or C, ormay be added with the monomer(s) of Component A continuously orstepwise, or may be added after completion of the addition of themonomer(s) of Component A.

In one embodiment, between about 50 and about 70 percent of themonomer(s) of Component A are introduced into the reactor during thefirst reaction period, by way of example but not limitation, during thefirst 10 minutes following initiation of the polymerization reaction(including monomers added prior to initiation of polymerization). Duringthe second reaction period, again by way of example but not limitation,of 10 minutes, the addition rate of the of Component A monomer(s)decreased such that about 25 to about 35 percent of the total ComponentA was added to the reactor. During the third and final illustrative 10minute reaction period, the addition rate of the Component A monomer(s)is again decreased so that the remaining about 5 to about 15 percent isadded to the reactor.

Examples of ethylenically unsaturated monomers capable of forminghydrolysable monomer residues comprising Component A that can becopolymerized include but are not limited to unsaturated monocarboxylicacid ester derivatives such as alkyl acrylates such as methyl acrylate,ethyl acrylate, propyl acrylate, and butyl acrylate; alkyl methacrylatessuch as methyl methacrylate, ethyl methacrylate, propyl methacrylate,and butyl methacrylate; hydroxyalkyl acrylates such as hydroxyethylacrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate;hydroxyalkyl methacrylates such as hydroxyethyl methacrylate,hydroxypropyl methacrylate, and hydroxybutyl methacrylate; acrylamide,methacrylamide, and derivatives thereof; maleic acid alkyl orhydroxyalkyl diesters; maleic anhydride or maleimide for copolymers tobe stored in the dry phase.

Examples of ethylenically unsaturated monomers capable of formingmonomer residues comprising Components B and/or C that can becopolymerized, whether hydrolysable or non-hydrolysable, includeunsaturated monocarboxylic acid ester derivatives such as polyethyleneglycol mono(meth)acrylate, polypropylene glycol (meth)acrylate,polybutylene glycol (meth)acrylate, polyethylene glycol polypropyleneglycol mono(meth)acrylate, polyethylene glycol polybutylene glycolmono(meth)acrylate, polypropylene glycol polybutylene glycolmono(meth)acrylate, polyethylene glycol polypropylene glycolpolybutylene glycol mono(meth)acrylate, methoxypolyethylene glycolmono(meth)acrylate, methoxypolypropylene glycol mono(meth)acrylate,methoxypolybutylene glycol mono(meth)acrylate, methoxypolyethyleneglycol polypropylene glycol mono(meth)acrylate, methoxypolyethyleneglycol polybutylene glycol mono(meth)acrylate, methoxypolypropyleneglycol polybutylene glycol mono(meth)acrylate, methoxypolyethyleneglycol polypropylene glycol polybutylene glycol mono(meth)acrylate,ethoxypolyethylene glycol mono(meth)acrylate, ethoxypolypropylene glycolmono(meth)acrylate, ethoxypolybutylene glycol mono(meth)acrylate,ethoxypolyethylene glycol polypropylene glycol mono(meth)acrylate,ethoxypolyethylene glycol polybutylene glycol mono(meth)acrylate,ethoxypolypropylene glycol polybutylene glycol mono(meth)acrylate,ethoxypolyethylene glycol polypropylene glycol polybutylene glycolmono(meth)acrylate, and higher alkoxy derivatives of the above mentionedpolyoxyalkylenes;

vinyl alcohol derivatives such as polyethylene glycol mono(meth)vinylether, polypropylene glycol mono(meth)vinyl ether, polybutylene glycolmono(meth)vinyl ether, polyethylene glycol polypropylene glycolmono(meth)vinyl ether, polyethylene glycol polybutylene glycolmono(meth)vinyl ether, polypropylene glycol polybutylene glycolmono(meth)vinyl ether, polyethylene glycol polypropylene glycolpolybutylene glycol mono(meth)vinyl ether, methoxypolyethylene glycolmono(meth)vinyl ether, methoxypolypropylene glycol mono(meth)vinylether, methoxypolybutylene glycol mono(meth)vinyl ether,methoxypolyethylene glycol polypropylene mono(meth)vinyl ether,methoxypolyethylene glycol polybutylene glycol mono(meth)vinyl ether,methoxypolypropylene glycol polybutylene glycol mono(meth)vinyl ether,methoxypolyethylene glycol polypropylene glycol polybutylene glycolmono(meth)vinyl ether, ethoxypolyethylene glycol mono(meth)vinyl ether,ethoxypolypropylene glycol mono(meth)vinyl ether, ethoxypolybutyleneglycol mono(meth)vinyl ether, ethoxypolyethylene glycol polypropyleneglycol mono(meth)vinyl ether, ethoxypolyethylene glycol polybutyleneglycol mono(meth)vinyl ether, ethoxypolypropylene glycol polybutyleneglycol mono(meth)vinyl ether, ethoxypolyethylene glycol polypropyleneglycol polybutylene glycol mono(meth)vinyl ether, and the like;

(meth)allyl alcohol derivatives such as polyethylene glycolmono(meth)allyl ether, polypropylene glycol mono(meth)allyl ether,polybutylene glycol mono(meth)allyl ether, polyethylene glycolpolypropylene glycol mono(meth)allyl ether, polyethylene glycolpolybutylene glycol mono(meth)allyl ether, polypropylene glycolpolybutylene glycol mono(meth)allyl ether, polyethylene glycolpolypropylene glycol polybutylene glycol mono(meth)allyl ether,methoxypolyethylene glycol mono(meth)allyl ether, methoxypolypropyleneglycol mono(meth)allyl ether, methoxypolybutylene glycol mono(meth)allylether, methoxypolyethylene glycol polypropylene glycol mono(meth)allylether, methoxypolyethylene glycol polybutylene glycol mono(meth)allylether, methoxypolypropylene glycol polybutylene glycol mono(meth)allylether, methoxypolyethylene glycol polypropylene glycol polybutyleneglycol mono(meth)allyl ether, ethoxypolyethylene glycol mono(meth)allylether, ethoxypolypropylene glycol mono(meth)allyl ether,ethoxypolybutylene glycol mono(meth)allyl ether, ethoxypolyethyleneglycol polypropylene glycol mono(meth)allyl ether, ethoxypolyethyleneglycol polybutylene glycol mono(meth)allyl ether, ethoxypolypropyleneglycol polybutylene glycol mono(meth)allyl ether, ethoxypolyethyleneglycol polypropylene glycol polybutylene glycol mono(meth)allyl ether,and the like;

adducts of 1 to 350 moles of alkylene oxide with an unsaturated alcoholsuch as 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol,2-methyl-3-buten-2-ol, 2-methyl-2-buten-1-ol, and 2-methyl-3-buten-1-ol,either alone respectively or in combinations with each other, includingbut not limited to polyethylene glycol mono (3-methyl-3-butenyl) ether,polyethylene glycol mono (3-methyl-2-butenyl) ether, polyethylene glycolmono (2-methyl-3-butenyl) ether, polyethylene glycol mono(2-methyl-2-butenyl) ether, polyethylene glycol mono(1,1-dimethyl-2-propenyl) ether, polyethylene polypropylene glycol mono(3-methyl-3-butenyl) ether, polypropylene glycol mono(3-methyl-3-butenyl) ether, methoxypolyethylene glycol mono(3-methyl-3-butenyl) ether, ethoxypolyethylene glycol mono(3-methyl-3-butenyl) ether, 1-propoxypolyethylene glycol mono(3-methyl-3-butenyl) ether, cyclohexyloxypolyethylene glycol mono(3-methyl-3-butenyl) ether, 1-ocyloxypolyethylene glycol mono(3-methyl-3-butenyl) ether, nonylalkoxypolyethylene glycol mono(3-methyl-3-butenyl) ether, laurylalkoxypolyethylene glycol mono(3-methyl-3-butenyl) ether, stearylalkoxypolyethylene glycol mono(3-methyl-3-butenyl) ether, and phenoxypolyethylene glycol mono(3-methyl-3-butenyl) ether, and the like.

Examples of ethylenically unsaturated monomers capable of formingnon-hydrolysable monomer residues comprising Component D includestyrene, ethylene, propylene, isobutene, alpha-methyl styrene, methylvinyl ether, and the like.

No monomer is added to the copolymer to introduce charge into themolecule prior to hydrolysis of the hydrolysable moiety of the ComponentA monomer residue in an alkaline environment, including but not limitedto the cementitious composition.

The subject non-ionic copolymer may have a weight average molecularweight of about 5,000 to about 150,000, in some embodiments about 25,000to about 55,000.

The subject non-ionic copolymer can be added to the cementitious mixturewith the initial batch water or as a delayed addition, in a dosage rangeof about 0.01 to about 3 percent copolymer based on the weight ofcementitious materials, and in certain embodiments, about 0.02 to about1 weight percent copolymer based on the weight of cementitiousmaterials.

The present process utilizing the subject non-ionic copolymers may beused in ready mix or pre-cast applications to provide differentiableworkability retention and all of the benefits associated therewith.Suitable applications include flatwork, paving (which is typicallydifficult to air entrain by conventional means), vertical applications,and precast articles. Further, the subject non-ionic copolymers haveshown particular value in workability retention of highly filledcementitious mixtures such as those containing large amounts of inertfillers, including but not limited to limestone powder. By “highlyfilled” is meant that the fillers, discussed in more detail below,comprise greater than about 10 weight percent, based on the weight ofcementitious material (hydraulic cement).

The subject non-ionic copolymers may be used in combination with atleast one type of water reducing composition, referred to generally asdispersants, to provide a combination of early workability, waterreduction and extended workability. In various embodiments, thedispersant may be at least one of traditional water reducers such aslignosulfonates, melamine sulfonate resins, sulfonated melamineformaldehyde condensates, salts of sulfonated melamine sulfonatecondensates, beta naphthalene sulfonates, naphthalene sulfonateformaldehyde condensate resins, or salts of sulfonated naphthalenesulfonate condensates; or, conventional polycarboxylate, polyaspartate,or oligomeric dispersants.

Examples of polycarboxylate dispersants can be found in U.S. PublicationNo. 2002/0019459 Al, U.S. Publication No. 2006/0247402 Al, U.S. Pat. No.6,267,814, U.S. Pat. No. 6,290,770, U.S. Pat. No. 6,310,143, U.S. Pat.No. 6,187,841, U.S. Pat. No. 5,158,996, U.S. Pat. No. 6,008,275, U.S.Pat. No. 6,136,950, U.S. Pat. No. 6,284,867, U.S. Pat. No. 5,609,681,U.S. Pat. No. 5,494,516, U.S. Pat. No. 5,674,929, U.S. Pat. No.5,660,626, U.S. Pat. No. 5,668,195, U.S. Pat. No. 5,661,206, U.S. Pat.No. 5,358,566, U.S. Pat. No. 5,162,402, U.S. Pat. No. 5,798,425, U.S.Pat. No. 5,612,396, U.S. Pat. No. 6,063,184, U.S. Pat. No. 5,912,284,U.S. Pat. No. 5,840,114, U.S. Pat. No. 5,753,744, U.S. Pat. No.5,728,207, U.S. Pat. No. 5,725,657, U.S. Pat. No. 5,703,174, U.S. Pat.No. 5,665,158, U.S. Pat. No. 5,643,978, U.S. Pat. No. 5,633,298, U.S.Pat. No. 5,583,183, U.S. Pat. No. 6,777,517, U.S. Pat. No. 6,762,220,U.S. Pat. No. 5,798,425, and U.S. Pat. No. 5,393,343, which are allincorporated herein by reference, as if fully written out below.

Examples of polyaspartate dispersants can be found in U.S. Pat. No.6,429,266; U.S. Pat. No. 6,284,867; U.S. Pat. No. 6,136,950; and U.S.Pat. No. 5,908,885, which are all incorporated herein by reference, asif fully written out below.

Examples of oligomeric dispersants can be found in U.S. Pat. No.6,133,347; U.S. Pat. No. 6,451,881; U.S. Pat. No. 6,492,461; U.S. Pat.No. 6,861,459; and U.S. Pat. No. 6,908,955, which are all incorporatedherein by reference, as if fully written out below.

When used in combination with a traditional water reducing dispersant ora conventional polycarboxylate, polyaspartate, or oligomeric dispersantin order to provide initial slump and to tailor workability of acementitious mixture for a specific application, the subject non-ioniccopolymer can be added to the cementitious mixture with the initialbatch water or as a delayed addition, in a dosage range of about 0.01 toabout 3 weight percent non-ionic copolymer based on the weight ofcementitious materials, and in certain embodiments, about 0.02 to about1 weight percent copolymer, and the traditional water reducingdispersant or conventional dispersant can be added to the cementitiousmixture with the initial batch water or as a delayed addition to thecementitious mixture , in a dosage range of about 0.01 to about 3 weightpercent dispersant based on the weight of cementitious materials, and incertain embodiments, about 0.02 to about 1 weight percent dispersant.

The cementitious compositions described herein may contain otheradditives or ingredients and should not be limited to the stated orexemplified formulations. Cement additives that can be addedindependently include, but are not limited to: air entrainers,aggregates, pozzolans, other fillers, set and strengthaccelerators/enhancers, set retarders, water reducers, corrosioninhibitors, wetting agents, water soluble polymers, rheology modifyingagents, water repellents, fibers, dampproofing admixtures, permeabilityreducers, pumping aids, fungicidal admixtures, germicidal admixtures,insecticide admixtures, finely divided mineral admixtures,alkali-reactivity reducer, bonding admixtures, shrinkage reducingadmixtures, and any other admixture or additive that does not adverselyaffect the properties of the cementitious composition. The cementitiouscompositions need not contain one of each of the foregoing additives.

Aggregate can be included in the cementitious formulation to provide formortars which include fine aggregate, and concretes which also includecoarse aggregate. The fine aggregates are materials that almost entirelypass through a Number 4 sieve (ASTM C125 and ASTM C33), such as silicasand. The coarse aggregates are materials that are predominantlyretained on a Number 4 sieve (ASTM C125 and ASTM C33), such as silica,quartz, crushed marble, glass spheres, granite, limestone, calcite,feldspar, alluvial sands, sands or any other durable aggregate, andmixtures thereof

Fillers for cementitious compositions may include aggregate, sand,stone, gravel, pozzolan, finely divided minerals, such as raw quartz,limestone powder, fibers, and the like, depending upon the intendedapplication. As non-limiting examples, stone can include river rock,limestone, granite, sandstone, brownstone, conglomerate, calcite,dolomite, marble, serpentine, travertine, slate, bluestone, gneiss,quartzitic sandstone, quartzite and combinations thereof.

A pozzolan is a siliceous or aluminosiliceous material that possesseslittle or no cementitious value but will, in the presence of water andin finely divided form, chemically react with the calcium hydroxideproduced during the hydration of portland cement to form materials withcementitious properties. Diatomaceous earth, opaline cherts, clays,shales, fly ash, slag, silica fume, volcanic tuffs and pumicites aresome of the known pozzolans. Certain ground granulated blast-furnaceslags and high calcium fly ashes possess both pozzolanic andcementitious properties. Natural pozzolan is a term of art used todefine the pozzolans that occur in nature, such as volcanic tuffs,pumices, trasses, diatomaceous earths, opaline, cherts, and some shales.Fly ash is defined in ASTM C618.

If used, silica fume can be uncompacted or can be partially compacted oradded as a slurry. Silica fume additionally reacts with the hydrationbyproducts of the cement binder, which provides for increased strengthof the finished articles and decreases the permeability of the finishedarticles. The silica fume, or other pozzolans such as fly ash orcalcined clay such as metakaolin, can be added to the cementitiousmixture in an amount from about 5% to about 70% based on the weight ofcementitious material.

The present process is useful in the production of precast, ready mix,and/or highly filled cementitious compositions.

Precast Cementitious Compositions:

The term “precast” cementitious compositions or precast concrete refersto a manufacturing process in which a hydraulic cementitious binder,such as Portland cement, and aggregates, such as fine and courseaggregate, are placed into a mold and removed after curing, such thatthe unit is manufactured before delivery to a construction site.

Precast applications include, but are not limited to, precastcementitious members or parts such as beams, double-Ts, pipes, insulatedwalls, prestressed concrete products, and other products where thecementitious composition is poured directly into forms and final partsare transported to job sites.

The production of precast cementitious members usually involves theincorporation of steel reinforcement. The reinforcement may be presentas structural reinforcement due to the designed use of the member inwhich it is included, or the steel may simply be present to allow for amember (such as a curtain wall panel) to be stripped from its moldwithout cracking

As used herein, “pre-stressed” concrete refers to concrete whose abilityto withstand tensile forces has been improved by using prestressingtendons (such as steel cable or rods), which are used to provide aclamping load producing a compressive strength that offsets the tensilestress that the concrete member would otherwise experience due to abending load.

Any suitable method known in the art can be used to pre-stress concrete.Suitable methods include, but are not limited to pre-tensioned concrete,where concrete is cast around already tensioned tendons, andpost-tensioned concrete, where compression is applied to the concretemember after the pouring and curing processes are completed.

In certain precast applications, it is desired that the cementitiouscomposition mixture have sufficient fluidity that it flows through andaround the reinforcement structure, if any, to fill out the mold andlevel off at the top of the mold, and consolidates without the use ofvibration. This technology is commonly referred to as self-consolidatingconcrete (SCC). In other embodiments, the mold may need to be agitatedto facilitate the leveling-off of the mixture, such as by vibrationmolding and centrifugal molding. In addition to the requirement forworkability retention, there is a requirement for the cementitiouscomposition to achieve fast setting times and high early strength.

With respect to precast applications, the term “high early strength”refers to the compressive strength of the cementitious mass within agiven time period after pouring into the mold. Therefore, it isdesirable that the cementitious composition mixture has initial fluidityand maintains fluidity until placement, but also has high early strengthbefore and by the time that the precast concrete units are to be removedfrom the mold.

High early-strength reinforced pre-cast or cast in place cementitiousmembers produced without metal bar, metal fiber or metal rodreinforcement that comprise hydraulic cement, polycarboxylatedispersant, and structural synthetic fibers are disclosed in commonlyowned U.S. Pat. No. 6,942,727, incorporated herein by reference.

To achieve the high strengths of precast cementitious compositions, verylow water to cement ratios are used. This necessitates a significantamount of high-range water reducer

(HRWR) to produce a workable mixture. Traditional HRWR chemistry such asnaphthalene sulfonate formaldehyde condensates will potentially retardset at such high dosages, and thereby inhibit the development of thehigh early strength necessary for stripping the member from the mold.

Typically early-strength development refers to compressive strengthsbeing achieved in 12-18 hours after placing the unset cementitiouscomposition in the mold.

To achieve a rapid level of strength development in the formation ofpre-cast cementitious members without an external heat source,traditional dispersant chemistries would not be successful because oftheir excessive retarding effect on cement hydration.

In precast applications, the water to cement ratio is typically aboveabout 0.2 but less than or equal to about 0.45.

A process is provided for making cast in place and pre-cast cementitiousmembers. The method comprises mixing a cementitious compositioncomprising hydraulic cement, such as portland cement, and the abovedescribed non-ionic copolymers with water, and optionally coarseaggregate, fine aggregate, structural synthetic fibers, or otheradditives, such as additives to control shrinkage and/or alkali-silicareaction, then forming the member from the mixture. Forming can be anyconventional method, including placing the mixture in a mold to set orcure and stripping away the mold.

The precast cementitious members or articles formed by the above processcan be used in any application but are useful for architectural,structural and non-structural applications. As examples but not by wayof limitation, the precast articles can be formed as wall panels, beams,columns, pipes, manholes (inclined walls), segments, precast plates, boxculverts, pontoons, double-Ts, U-tubes, L-type retaining walls, beams,cross beams, road or bridge parts and various blocks or the like.However, the precast concrete articles are not limited to such specificexamples.

Ready Mix and Highly Filled Cementitious Compositions:

As used herein, the term “ready mix” refers to cementitious compositionthat is batch mixed or “batched” for delivery from a central plantinstead of being mixed on a job site. Typically, ready mix concrete istailor-made according to the specifics of a particular constructionproject and delivered ideally in the required workability in “ready mixconcrete trucks”.

Over the years, the use of fillers and/or pozzolanic materials as apartial replacement for portland cement in concrete has become anincreasingly attractive alternative to portland cement alone. The desireto increase the use of inert fillers and/or fly ash, blast furnace slag,and natural pozzolanic cement in concrete mixtures can be attributed toseveral factors. These include cement shortages, economic advantages ofportland cement replacement, improvements in permeability of theconcrete product, and lower heats of hydration.

Despite the cost and performance advantages of using inert or pozzolanicmaterials as partial replacements of portland cement in concrete, thereare practical limitations to the amount at which they can be used in thecementitious mixture. Using these materials at higher levels, such asabove about 10 weight percent based on the weight of the portlandcement, can result in the retarded setting time of the concrete up toseveral hours, and perhaps longer depending upon the ambienttemperature. This incompatibility puts a burden of increased costs andtime on the end user, which is unacceptable.

While it is known to use set time accelerators in concrete mixtures,these accelerator admixtures have been problematic, particularly whenused with water reducing admixtures, so that set time cannot bedecreased to an acceptable level. The use of accelerators with waterreducers, such as naphthalene sulfonate formaldehyde condensates, ligninand substituted lignins, sulfonated melamine formaldehyde condensatesand the like, has been ineffective to produce an acceptable highlyfilled or pozzolanic replacement containing hydraulic cement basedcementitious mixture with normal setting characteristics and anacceptable resulting concrete.

The subject nonionic copolymers in combination with a traditionaldispersant or a conventional polycarboxylate dispersant in cementitiouscompositions exhibit superior workability retention without retardation,minimize the need for slump adjustment during production and at thejobsite, minimize mixture over-design requirements, reduce re-dosing ofhigh-range water-reducers at the jobsite, and provide high flowabilityand increased stability and durability.

Slump is a measure of the consistency of concrete, and is a simple meansof ensuring uniformity of concrete on-site. To determine slump, astandard size slump cone is filled with fresh concrete. The cone is thenremoved, and the “slump” is the measured difference between the heightof the cone and the collapsed concrete immediately after removal of theslump cone.

EXAMPLES

Specific embodiments of non-ionic copolymers were tested according tothe examples set forth below, and compared with traditional dispersantsand conventional polycarboxylate dispersants. Conventionalpolycarboxylate dispersants typically comprise copolymers of carboxylicacid, derivatized carboxylic acid esters, and/or derivatized alkenylethers. The derivatives, or side chains, are generally long (greaterthan about 500 MW) and are generally not readily hydrolysable from thepolymer backbone in cementitious compositions.

Synthesis Example Copolymer A

A glass reactor vessel equipped with multiple necks, a mechanicalstirrer, pH-meter and dosing equipment (e.g. syringe pump) was chargedwith 138 g water and 182 g of molten vinyl-PEG 1100 (solution A). Thetemperature in the reactor was adjusted to 12° C. and the pH wasadjusted to approximately 7 by addition of 4 g of 25% sulfuric acidsolution.

A portion (59.63 g) of a previously prepared second solution, (solutionB), consisting of 228.17 g water and 79.22 g of hydroxyethyl acrylate(HEA, 98.5%) was added to the reactor vessel drop wise over a period of10 minutes while stirring moderately. A pH of 6.5 was measured for theresulting solution in the reactor. To the remaining solution B was added2.28 g 3-mercaptopropionic acid (3-MPA). A further amount of 0.76 g3-MPA was added to the reactor shortly before initiation ofpolymerization. A third solution, (solution C) containing 1.5 g ofsodium hydroxymethane sulfinate dihydrate in 48.5 g water was prepared.The polymerization was initiated by adding 31 mg FeSO₄×7H₂O in severalmilliliters of water and 2.01 g of H₂O₂ (30%) solution to the reactionvessel. Simultaneously, the dosing of solution B and C was started intothe polymerization vessel. Solution B was dosed over a period of 30minutes using varying addition rates as described in the table below.Solution C was dosed at a constant speed of 4.5 g/h over a period of 30min followed by a higher dosing speed of 75 g/h over an additional 6minutes. During the 30 minute dosing period of solution B, the pH in thereactor was maintained at 6.5 by adding 20% aqueous NaOH solution. ThepH of the polymer solution after the addition of solution C was 7.1 and0.24 g of 25% sulfuric acid solution was added to adjust the pH to 7. Anaqueous solution of a polyether-polyester copolymer with a yield of97.7%, a weight-average molecular weight of 37,300 g/mole, a PDI of 1.91as determined by SEC and a solids content of 38.9% was obtained.

Ramp Table A t (min) 0 2 4 8 10 12 14 16 18 22 26 30 g/h 728 808 843 808728 594 488 390 301 186 115 0

Synthesis Example Copolymer B

A glass reactor vessel equipped with multiple necks, a mechanicalstirrer, pH-meter and dosing equipment (e.g. syringe pump) was chargedwith 267 g of water and 330.9 g of molten vinyl-PEG 3000 (solution A).The temperature in the reactor was adjusted to 13° C. and the pH wasadjusted to approximately 7 by addition of 3 g of 25% sulfuric acidsolution.

A portion (20.5 g) of a previously prepared second solution (solutionB), consisting of 152.11 g water and 52.82 g of hydroxyethyl acrylate(HEA, 98.5%) was added to the reactor vessel drop wise over a period of10 minutes under moderate stirring. A pH of 6.8 was measured for theresulting solution in the reactor. To the remaining solution B was added2.9 g 3-mercaptopropionic acid (3-MPA). A further amount of 0.52 g 3-MPAwas added to the reactor shortly before initiation of polymerization. Athird solution, (solution C) containing 1.5 g of sodium hydroxymethanesulfinate dihydrate in 48.5 g water was prepared. The polymerization wasinitiated by adding 21 mg FeSO₄×7H₂O that was dissolved in severalmilliliters of water and 1.34 g of H₂O₂ (30%) solution to the reactionvessel. Simultaneously, the dosing of solution B and C into thepolymerization vessel was started. Solution B was dosed over a period of30 minutes using varying addition rates as described in the table below.Solution C was dosed at a constant speed of 1.54 g/h over a period of 30minutes followed by a higher dosing speed of 50 g/h over an additional10 minutes. During the 30 minute dosing period of solution B, the pH inthe reactor was maintained at 6.8 by adding 20% aqueous NaOH solution.The pH of the polymer solution after the addition of solution C was 7.1and 0.2 g of 25% sulfuric acid was added to adjust the pH to 7. Anaqueous solution of a polyether-polyester copolymer with a yield of 91%,a weight-average molecular weight of 37,000 g/mole, a PDI of 1.47 asdetermined by SEC and a solids content of 46.8% was obtained.

Ramp Table B t (min) 0 2 4 8 10 12 14 16 18 22 26 30 g/h 549 609 635 609549 448 368 294 227 140 87 0

Examples 1 and 2 and Comparative Examples 3, 4 and 5

Sample cementitious compositions suitable for use in pre-castapplications were prepared by first introducing a slump affectingadmixture and defoamer into the mix water in the amounts listed in Table1 below. The stone, cement and sand were added in the amounts shown inTable 1, and the mixture was mixed for five minutes at 20 rpm in a drummixer. The slump of a sample of this mixture was tested (test durationapproximately two minutes), and mixing resumed within five minutes, atfour rpm. Mixing cycles of 20 minutes followed by test cycles of fiveminutes were repeated to generate the data shown in Table 1. Thecomposition of Example 1 included Copolymer A having Component Ahydroxyethylacrylate residues and Component B polyethylene glycol vinylether residues in a molar ratio of 4:1, that of Example 2 includedCopolymer B having Component A hydroxyethylacrylate residues andComponent C polyethylene glycol vinyl ether residues in a molar ratio of4:1, that of Comparative Example 3 contained no slump affectingadmixture or defoamer, and the compositions of Comparative Examples 4and 5 included conventional polycarboxylate dispersants.

The slump of the test compositions was determined by placing a cone on aflat surface, filling the cone with the cementitious composition, andremoving the cone, as described in ASTM C143. The composition would thenflow, and the displaced height (slump) of the resulting mound of thecementitious composition, as well as the diameter (slump flow) of thebase of the mound, were measured in inches.

The workability of each cementitious composition, as represented by itsslump, was determined according to ASTM C143, reported in Table 1,below. The slump diameter, or diameter of the base of the slumpedconcrete, of each composition was also measured, as well as the aircontent (ASTM C231), reported in Table 1. As shown in Table 1 and FIGS.1 and 2, Copolymers A and B used in Examples 1 and 2 had initial slumpmeasurements comparable to the additive-free control composition ofComparative Example 3, however, workability increased and was maintainedover time. In contrast, the conventional polycarboxylate dispersantsutilized in Comparative Examples 4 and 5, developed maximum workabilityquickly, and tended to lose workability over time. In this respect, theCopolymers A & B demonstrated performance characteristics opposite tothose of the conventional dispersants.

TABLE 1 Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 AdmixtureCopolymer Copolymer None Conventional Conventional A B PolycarboxylatePolycarboxylate Dose (% wt cmt) 0.16 0.16 — 0.1 0.1 Defoamer TBP TBPNone TBP TBP Dose (% wt cmt) 0.004 0.004 — 0.004 0.004 Cement (lbs/yd3)644 644 645 648 645 Sand (lbs/yd3) 1310 1310 1312 1318 1311 Stone 1(lbs/yd3) 1863 1863 1866 1874 1865 Water (lbs/yd3) 271 271 272 273 271Water/Cement 0.42 0.42 0.42 0.42 0.42 Sand/Aggregate 0.43 0.43 0.43 0.430.43 Slump (in)  5 Min 4.50 5.00 4.00 9.25 8.75 30 Min 8.50 7.75 3.509.75 8.25 55 Min 8.25 8.00 3.25 8.25 8.25 80 Min 8.25 7.00 2.50 7.507.50 Slump Diameter (in)  5 Min — — — 22.00 13.50 30 Min 13.25 11.25 —23.00 13.25 55 Min 14.00 12.25 — 14.00 13.25 80 Min 13.25 9.75 — 10.75 —Air Content (%)  5 Min 2.5 2.5 2.3 1.9 2.4 80 Min 2.4 2.7 2.3 2.4 2.4Initial Gravimetric 2.5 2.5 2.4 2.1 2.1 Air Content (%)

Examples 6 and 7 and Comparative Example 8

Sample cementitious compositions were prepared by first introducing theadmixture and defoamer into the mix water in the amounts listed in Table2 below. The stone, cement, and sand were added in the amounts shown inTable 2, and the mixture was mixed for five minutes at 20 rpm in a drummixer. The slump of a sample of this mixture was tested (test durationapproximately two minutes), and mixing resumed within five minutes, atfour rpm. Mixing cycles of 20 minutes followed by test cycles of fiveminutes were repeated to generate the data shown in Table 2. Thecomposition of Example 6 included Copolymer B, having Component Ahydroxyethylacrylate residues and Component C polyethylene glycol vinylether residues, that of Example 7 included Copolymer A having ComponentA hydroxyethylacrylate residues and Component B polyethylene glycolvinyl ether residues, and that of Comparative Example 8 included aconventional polycarboxylate dispersant.

The workability of each cementitious composition, as represented by itsslump, was determined according to ASTM C143, reported in Table 2,below. The air content, set time (ASTM C403), and compressive strength(ASTM C39) of each composition were also determined and reported inTable 2. As shown in Table 2 and FIG. 3, Copolymers A and B used inExamples 6 and 7 produced opposite workability performancecharacteristics over time as compared to the polycarboxylate dispersantutilized in Comparative Example 8, while not sacrificing air content,set time, or compressive strength. The conventional polycarboxylatedispersant produced maximum concrete workability quickly, which was lostover time. In contrast, Copolymers A and B produced low initialworkability and maximum workability after 55 minutes. Initial slump wasnot affected by the addition of the non-ionic copolymers, but use of thenon-ionic copolymers as compared to the polycarboxylate dispersantimproved slump retention, as the slump exhibited by the polycarboxylatedispersant containing mixture was initially high but steadily decreased.

TABLE 2 Ex. 6 Ex. 7 Comp. Ex. 8 Admixture Copolymer CopolymerConventional B A Polycarboxylate Dose (% wt cmt) 0.1 0.1 0.1 DefoamerTBP TBP TBP Dose (% wt cmt) 0.003 0.003 0.003 Cement (lbs/yd3) 565 565566 Sand (lbs/yd3) 1356 1356 1359 Stone 1 (lbs/yd3) 1309 1309 1312 Stone2 (lbs/yd3) 562 562 563 Water (lbs/yd3) 280 280 281 Water/Cement 0.500.50 0.50 Sand/Aggregate 0.44 0.44 0.44 Slump (in)  5 Min 3.00 3.50 8.5030 Min 5.50 7.50 7.75 55 Min 7.25 6.75 5.75 80 Min 5.25 4.00 3.50 AirContent (%)  5 Min 1.9 1.9 1.7 80 Min 1.8 1.9 1.8 Initial GravimetricAir 2.0 1.9 0.8 Content (%) Initial Set (hrs) 4.2 4.1 4.1 Final Set 5.85.6 5.6 Compressive Strengths (psi)  1 Day 2020 2000 2120  6 Day 48504760 4880 28 Day 6280 6180 6240

Synthesis Example Copolymer C

A glass reactor vessel equipped with multiple necks, a mechanicalstirrer, pH-meter and dosing equipment (e.g. syringe pump) was chargedwith 100 g of water and 60.67 g of molten vinyl-PEG 1100 (solution A).The temperature in the reactor was adjusted to 13° C. and the pH wasadjusted to approximately 7 by addition of 0.28 g of 25% sulfuric acidsolution.

A second solution (solution B), consisting of 152.11 g water and 52.82 gof hydroxyethyl acrylate (HEA, 98.5%) was prepared. To solution B wasadded 1.74 g 3-mercaptopropionic acid (3-MPA). A third solution,(solution C) containing 1.5 g of sodium hydroxymethane sulfinatedihydrate in 48.5 g water was prepared. The polymerization was initiatedby adding 21 mg FeSO₄×7H₂O that was dissolved in several milliliters ofwater and 1.34 g of H₂O₂ (30%) solution to the reaction vessel.Simultaneously, the dosing of solution B and C into the polymerizationvessel was started. Solution B was dosed over a period of 30 minutesusing varying addition rates as described in the table below. Solution Cwas dosed at a constant speed of 1.54 g/h over a period of 30 minutesfollowed by a higher dosing speed of 50 g/h over an additional 10minutes. During the 30 minute dosing period of solution B, the pH in thereactor was maintained at 5.9 by adding 20% aqueous NaOH solution. ThepH of the polymer solution after the addition of solution C was 5.9 andclimbed to 6.8 upon destruction of remaining amounts of H₂O₂. An aqueoussolution of a polyether-polyester copolymer with a yield of 92.5%, aweight-average molecular weight of 28300 g/mole, a PDI of 1.68 asdetermined by SEC and a solid content of 28.3% was obtained.

Ramp Table C t (min) 0 2 4 8 10 12 14 16 18 22 26 30 g/h 606 673 702 673606 495 407 325 251 155 96 0

Synthesis Example Copolymer D

A glass reactor equipped with multiple necks, stirrer, pH meter andreflux-condenser was charged with 410 g water and 350 g of moltenvinyl-PEG 3000. The temperature in the reactor was adjusted to 13° C.0.5 g of a 2% FeSO₄×7H₂O solution and 124 g of hydroxyethylacrylate(HEA, 98%) were added, followed by addition of 3.4 g 3-Mercaptopropionicacid (3-MPA) and 4 g of ascorbic acid. The resulting pH was 5.5. After 2min of mixing 1.2 g of H₂O₂ (50%) were added. Shortly thereafter atemperature rise was observed, peaking at 45° C. at 3 min while pHdropped to 4.7. After additional 5 min the pH of the solution isadjusted to pH=6.5 with 7 g of NaOH (20%). An aqueous solution of apolyether-polyester copolymer with a yield of 92.5%, a weight-averagemolecular weight of 28300 g/mole, a PDI of 1.68 as determined by SEC anda solid content of 53% was obtained.

Synthesis Example Copolymer E

A glass reactor vessel equipped with multiple necks, a mechanicalstirrer, pH-meter and dosing equipment (e.g. syringe pump) was chargedwith 320 g water and 320 g of molten vinyl-PEG 5800 (solution A). Thetemperature in the reactor was adjusted to 13° C. and the pH wasadjusted to approximately 7 by addition of 3.4 g of 25% sulfuric acidsolution.

A portion (19.88 g) of a previously prepared second solution, (solutionB), consisting of 75.78 g water and 26.68 g of hydroxyethyl acrylate(HEA, 98.5%) was added to the reactor vessel drop wise over a period of10 minutes while stirring moderately. A pH of 6.5 was measured for theresulting solution in the reactor. To the remaining solution B was added2.7 g 3-mercaptopropionic acid (3-MPA). A further amount of 0.9 g 3-MPAwas added to the reactor shortly before initiation of polymerization. Athird solution, (solution C) containing 1.5 g of sodium hydroxymethanesulfinate dihydrate in 48.5 g water was prepared. The polymerization wasinitiated by adding 11 mg FeSO₄×7H₂O in several milliliters of water and2.0 g of H₂O₂ (30%) solution to the reaction vessel. Simultaneously, thedosing of solution B and C was started into the polymerization vessel.Solution B was dosed over a period of 22 minutes. Solution C was dosedat a constant speed of 1.5 g/h over a period of 22 min followed by ahigher dosing speed of 50 g/h over an additional 22 minutes usingvarying addition rates as described in the table below. During the 30minute dosing period of solution B, the pH in the reactor was maintainedat 6.4 by adding 20% aqueous NaOH solution. A pH of 6.4 was measured forthe polymer solution after the addition of solution C was complete. Anaqueous solution of a polyether-polyester copolymer with a yield of86.2%, a weight-average molecular weight of 37,500 g/mole, a PDI of 1.3as determined by SEC and a solids content of 45.2% was obtained.

Ramp Table E t (min) 0 2 4 8 10 12 14 16 18 22 g/h 270 313 342 313 261218 173 124 85 0

Synthesis Example Copolymer F

A glass reactor equipped with multiple necks, stirrer, pH meter andreflux-condenser was charged with 500 g water and 350 g of moltenvinyl-PEG 5800. The temperature in the reactor was adjusted to 13° C.0.5 g of a 2% FeSO₄×7H₂O solution and 85.7 g of hydroxyethylacrylate(HEA, 98%) were added, followed by addition of 2.2 g 3-Mercaptopropionicacid (3-MPA) and 2 g of ascorbic acid. The resulting pH was 5.5. After 2min of mixing 0.6 g of H₂O₂ (50%) were added. Shortly thereafter aT-rise is observed, peaking at 32° C. at 3 min while pH dropped to 5.1.After additional 5 min the pH of the solution is adjusted to pH=6.5 with5 g of NaOH (20%). An aqueous solution of a polyether-polyestercopolymer with a yield of 92.5%, a weight-average molecular weight of52500 g/mole, a PDI of 1.52 as determined by SEC and a solid content of45.8% was obtained.

Examples 8-13 and Comparative Example 14

Sample cementitious compositions were prepared by first combining waterand polymer in the amounts listed in Table 3, below. The water solutionwas sampled and tested to determine the initial concentration ofpolymer. Cement was added to each test solution in the amount listed inTable 3, and the mixtures were then mixed at 700 rpm to form a paste. Asmall portion of the paste was then removed, pressure filtered toisolate the liquid phase present in the paste, and the concentration ofpolymer in the filtrate solution was determined. The original pastesample was returned to the mixer and the process was repeated to providethe data reported in Table 3 below. As shown in Table 3, the compositionof Example 8 included Copolymer A described above, that of Example 9included Copolymer C having Component A hydroxyethylacrylate residuesand Component B polyethylene glycol vinyl ether residues in a ratio of8:1, that of Example 10 included Copolymer B also described above, thatof Example 11 included Copolymer D having Component Ahydroxyethylacrylate residues and Component C polyethylene glycol vinylether residues in a ratio of 9:1, that of Example 12 included CopolymerE having Component A hydroxyethylacrylate residues and Component Cpolyethylene glycol vinyl ether residues in a ratio of 4:1, that ofExample 13 included Copolymer F having Component A hydroxyethylacrylateresidues and Component C polyethylene glycol vinyl ether residues in aratio of 12:1, and that of Comparative Example 14 included aconventional polycarboxylate dispersant.

As shown in Table 3 and FIG. 4, the copolymers described herein areadsorbed onto the cement particles more slowly than the conventionalpolycarboxylate dispersant, providing low initial affinity anddispersing effect, but increasing both upon hydrolysis of Component A toremain active for a longer period of time, and thus extending theworkability of the cementitious compositions to which they are added.

TABLE 3 Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex. 12 Ex. 13 Comp. Ex. 14 AdmixtureCopolymer A Copolymer C Copolymer B Copolymer D Copolymer E Copolymer FConventional Polycarboxylate Dose (% cmt) 0.1% 0.1% 0.1% 0.1% 0.1% 0.1%0.10% Cement (g) 1000 1000 1000 1000 1000 1000 1000 Water (g) 400 400400 400 400 400 400 Water/Cement 0.40 0.40 0.40 0.40 0.40 0.40 0.40Polymer Adsorption (%)  5 Min 26.0 33.6 2.4 35.0 −3.9 3.8 92.0 30 Min47.0 82.3 27.9 75.1 2.6 61.0 96.3 55 Min 70.4 97.7 42.9 92.6 13.2 82.697.4 80 Min 76.7 99.8 51.7 97.4 27.3 88.3 97.9 Polymer Adsorbed (mg/kgcmt)  5 Min 260 336 24 351 0 38 919 30 Min 470 822 279 752 26 609 962 55Min 704 976 429 928 132 825 973 80 Min 767 997 516 976 273 882 978

Examples 15 and 16

Hydrolysis rates of the subject copolymers at room temperature weretested by first combining sodium hydroxide and water, then adding thesubject copolymer. Samples of the mixtures were extracted at the timeslisted in Table 4, below, and tested to determine the hydrolysispercentage of the subject copolymers, as reported in Table 4. Thecopolymer Example 15 included hydroxyethylacrylate as the hydrolysableComponent A residue as described herein, while that of Example 16included hydroxypropylacrylate as the hydrolysable Component A residueas described herein. Both copolymers contained non-hydrolysableComponent B residues.

As shown in Table 4 and FIG. 5, the hydrolysis rates of the twocopolymers differ. This data demonstrates that hydrolysis rates can becontrolled by using different hydrolysable components in variousembodiments of subject copolymers, and further by mixing differentembodiments of the subject copolymers. By controlling the hydrolysisrate, the workability of the cementitious compositions to which thecopolymers are added can be controlled with precision.

TABLE 4 Elapsed Time Ex. 15 Ex. 16 (min) % Hydrolysis % Hydrolysis 0 0 05 15.4 11.3 30 40.3 33.2 55 47.1 38.7 80 50.1 40.4 240 60.3 55.2

Examples 17, 18 and 19 and Comparative Example 20

Sample cementitious compositions were prepared by first introducing theadmixture and defoamer into the mix water in the amounts listed in Table5 below. The stone, cement, fly ash, and sand were added in the amountsshown in Table 5, and the mixture was mixed for five minutes at 20 rpmin a drum mixer. The slump of a sample of this mixture was tested (testduration approximately two minutes), and mixing resumed within fiveminutes, at four rpm. Mixing cycles of 20 minutes followed by testcycles of five minutes were repeated to generate the data shown in Table5. The compositions of Examples 17 through 19 included differing ratiosof a combination of Copolymer B and a traditional lignosulfonate waterreducing dispersant, while that of Comparative Example 20 included onlythe lignosulfonate dispersant.

The workability of each cementitious composition, as represented by itsslump, was determined according to ASTM C143, reported in Table 5,below. The air content, set time (ASTM C403), and compressive strength(ASTM C39) of each composition were also determined and are reported inTable 5. As shown in Table 5 and FIG. 6, a combination of Copolymers Band a lignosulfonate dispersant, as used in Examples 17 through 19,maintain the workability of the cementitious compositions longer thanthe lignosulfonate dispersant utilized in Comparative Example 20, whilenot sacrificing air content, set time, or compressive strength. Further,as shown by the increased workability of Example 19 compared withExamples 17 and 18, an increased amount of Copolymer B performed betterthan lesser amounts of Copolymer B to increase slump retention.

TABLE 5 Ex. 17 Ex. 18 Ex. 19 Comp. Ex. 20 Dose (% cmt + FA) 0.004 0.0040.004 0.004 Defoamer TBP TBP TBP TBP Dose (% cmt + FA) 0.025 0.05 0.1 —Admixture Copolymer B Copolymer B Copolymer B — Dose (% cmt + FA) 0.250.25 0.25 0.25 Admixture Lignosulfonate Lignosulfonate LignosulfonateLignosulfonate Cement (lbs/yd3) 474 473 474 474 Fly Ash (FA) 109 109 109109 (lbs/yd3) Sand (lbs/yd3) 1397 1394 1395 1397 Stone 1 (lbs/yd3) 18251821 1823 1825 Water (lbs/yd3) 277 276 277 277 Water/Cement 0.47 0.470.47 0.47 Sand/Aggregate 0.45 0.45 0.45 0.45 Slump (in)  5 Min 8.00 8.008.75 7.75 30 Min 5.50 6.75 8.25 4.50 55 Min 4.50 5.75 7.50 3.50 80 Min3.25 3.50 6.50 3.00 Air Content (%)  5 Min 1.8 2.0 1.9 1.8 80 Min 1.61.7 1.7 1.5 Gravimetric Air (%) Initial 1.5 1.6 1.6 1.5 Initial Set(hrs) 6.5 6.8 7.6 6.2 Final Set (hrs) 8.2 8.4 9.1 7.9 CompressiveStrengths (psi)  1 Day 1710 1680 1540 1630  7 Day 4260 4180 4340 4410 28Day 6060 5910 6050 6160

Synthesis Example Copolymer G

A glass reactor vessel equipped with multiple necks, a mechanicalstirrer, pH-meter and dosing equipment (e.g. syringe pump) was chargedwith 55 g water and 99.3 g of molten vinyl-PEG 500 (solution A). Thetemperature in the reactor was adjusted to 13° C. and the pH wasadjusted to approximately 7 by addition of 0.3 g of 25% sulfuric acidsolution.

A portion (89.45 g) of a previously prepared second solution, (solutionB) consisting of 272.8 g water and 96.06 g of hydroxyethyl acrylate(HEA, 98.5%) was added to the reactor vessel drop wise over a period of10 minutes while stirring moderately. A pH of 6.4 was measured for theresulting solution in the reactor. To the remaining solution B was added1.65 g 3-mercaptopropionic acid (3-MPA). A further amount of 0.89 g3-MPA was added to the reactor shortly before initiation ofpolymerization. A third solution, (solution C) containing 1.5 g ofsodium hydroxymethane sulfinate dihydrate in 48.5 g water was prepared.The polymerization was initiated by adding 19 mg FeSO₄×7H₂O in severalmilliliters of water and 1.23 g of H₂O₂ (30%) solution to the reactionvessel. Simultaneously, the dosing of solution B and C was started intothe polymerization vessel. Solution B was dosed over a period of 30minutes using varying addition rates as described in the table below.Solution C was dosed at a constant speed of 4.5 g/h over a period of 30min followed by a higher dosing speed of 100 g/h over an additional 11minutes. During the 30 minute dosing period of solution B, the pH in thereactor was maintained at 6.4 by adding 20% aqueous NaOH solution. A pHof 6.7 was measured for the polymer solution after the addition ofsolution C was complete. An aqueous solution of a polyether-polyestercopolymer with a yield of 97.4%, a weight-average molecular weight of42,100 g/mole, a PDI of 2.31 as determined by SEC and a solids contentof 35.2% was obtained.

Ramp Table G t (min) 0 2 4 8 10 12 14 16 18 22 26 30 g/h 816 906 945 906816 667 548 438 338 209 129 0

Examples 21, 22 and 23, and Comparative Example 24

Sample cementitious compositions suitable for use in pre-castapplications were prepared by mixing the stone, cement, sand and water,in the amounts listed in Table 6, below, for five minutes at 20 rpm.After the first minute of mixing, the naphthalene sulfonate admixturewas added in the amount shown in Table 6. The initial slump and aircontent were then determined during the initial portion of the fiveminute test period, as reported in table 6. The second slump affectingadmixture, if present, was then added to the composition in the amountsshown in Table 6, and mixing was resumed for 20 minutes at four rpm. Theslump was again determined, as reported in Table 6. This process wasthen repeated to compile the data reported in Table 6. The compositionof Example 21 included Copolymer B discussed above, that of Example 22included Copolymer A discussed above, that of Example 23 includedCopolymer G having Component A hydroxyethylacrylate residues andComponent B polyethylene glycol vinyl ether residues in a molar ratio of4:1, and that of Comparative Example 24 did not include a slumpaffecting admixture.

The workability of each cementitious composition, as represented by itsslump, was determined according to ASTM C143, reported in Table 6,below. The air content, set time (ASTM C403), and compressive strength(ASTM C39) of each composition were also determined, reported in Table6. As shown in Table 6 and FIG. 7, the subject non-ionic copolymers,when used in combination with a traditional water reducing naphthalenesulfonate admixture, extended the workability of the cementitiouscomposition much more effectively than naphthalene sulfonate alone. Dueto slight incompatibility between naphthalene sulfonates and thenon-ionic copolymers, the addition of the copolymers was delayed untilthe traditional water reducer had been mixed in the cementitiouscomposition for about 10 minutes.

TABLE 6 Ex. 21 Ex. 22 Ex. 23 Comp. Ex. 24 Dose (% cmt) 0.004 0.004 0.0040.004 Defoamer TBP TBP TBP TBP Dose (% cmt) 0.20 0.20 0.20 — AdmixturePolymer B Copolymer A Copolymer G — Dose (% cmt) 0.55 0.55 0.55 0.55Admixture Naphthalene Naphthalene Naphthalene Naphthalene SulfonateSulfonate Sulfonate Sulfonate Cement (lbs/yd3) 672 672 672 656 Sand(lbs/yd3) 1294 1293 1294 1262 Stone 1 (lbs/yd3) 1910 1908 1910 1863Water (lbs/yd3) 247 247 247 275 Water/Cement 0.37 0.37 0.37 0.42Sand/Aggregate 0.42 0.42 0.42 0.42 Slump (in)  5 Min 7.25 7.00 8.50 8.0030 Min 7.75 7.00 8.00 3.00 55 Min 4.50 5.00 5.50 2.50 Total Slump Loss2.75 2.00 3.00 5.50 Air Content (%)  5 Min 2.6 2.7 2.6 3.0 80 Min 2.42.4 2.6 2.4 Gravametric Air (%) Initial 1.9 1.9 2.1 1.7 Initial Set(hrs) 5.7 5.9 6.6 4.9 Final Set (hrs) 7.0 7.3 7.9 6.0 CompressiveStrengths (psi)  1 Day 2800 2970 2630 2870  7 Day 6230 6300 5690 6240 28Day 7770 7910 7670 7710

Synthesis Example Copolymer H

A glass reactor vessel equipped with multiple necks, a mechanicalstirrer, pH-meter and dosing equipment (e.g. syringe pump) was chargedwith 267 g water and 330.9 g of molten vinyl-PEG 3000 (solution A). Thetemperature in the reactor was adjusted to 13° C. and the pH wasadjusted to approximately 7 by addition of 2.5 g of 25% sulfuric acidsolution.

A portion (44.95 g) of a previously prepared second solution, (solutionB) consisting of 169.86 g water and 59.81 g of hydroxypropyl acrylate(HPA, 96%) was added to the reactor vessel drop wise over a period of 10minutes while stirring moderately. A pH of 6.5 was measured for theresulting solution in the reactor. To the remaining solution B was added2.28 g 3-mercaptopropionic acid (3-MPA). A further amount of 0.76 g3-MPA was added to the reactor shortly before initiation ofpolymerization. A third solution, (solution C) containing 1.5 g ofsodium hydroxymethane sulfinate dihydrate in 48.5 g water was prepared.The polymerization was initiated by adding 21 mg FeSO₄×7H₂O in severalmilliliters of water and 1.34 g of H₂O₂ (30%) solution to the reactionvessel. Simultaneously, the dosing of solution B and C was started intothe polymerization vessel. Solution B was dosed over a period of 30minutes using varying addition rates as described in the table below.Solution C was dosed at a constant speed of 1.5 g/h over a period of 30min followed by a higher dosing speed of 50 g/h over an additional 10minutes. During the 30 minute dosing period of solution B, the pH in thereactor was maintained at 6.5 by adding 20% aqueous NaOH solution. A pHof 6.5 was measured for the polymer solution after the addition ofsolution C was complete. An aqueous solution of a polyether-polyestercopolymer with a yield of 93.3%, a weight-average molecular weight of51,500 g/mole, a PDI of 1.67 as determined by SEC and a solids contentof 46.1% was obtained.

Ramp Table H t (min) 0 2 4 8 10 12 14 16 18 22 26 30 g/h 545 605 631 605545 445 366 292 226 140 86 0

Synthesis Example Copolymer J

A glass reactor vessel equipped with multiple necks, a mechanicalstirrer, pH-meter and dosing equipment (e.g. syringe pump) was chargedwith 138 g water and 182 g of molten vinyl-PEG 1100 (solution A). Thetemperature in the reactor was adjusted to 13° C. and the pH wasadjusted to approximately 7 by addition of 3.75 g of 25% sulfuric acidsolution.

A portion (67.42 g) of a previously prepared second solution, (solutionB) consisting of 254.79 g water and 89.72 g of hydroxypropyl acrylate(HPA, 96%) was added to the reactor vessel drop wise over a period of 10minutes while stirring moderately. A pH of 6.5 was measured for theresulting solution in the reactor. To the remaining solution B was added2.46 g 3-mercaptopropionic acid (3-MPA). A further amount of 0.82 g3-MPA was added to the reactor shortly before initiation ofpolymerization. A third solution, (solution C) containing 1.5 g ofsodium hydroxymethane sulfinate dihydrate in 48.5 g water was prepared.The polymerization was initiated by adding 31 mg FeSO₄×7H₂O in severalmilliliters of water and 2.01 g of H₂O₂ (30%) solution to the reactionvessel. Simultaneously, the dosing of solution B and C was started intothe polymerization vessel. Solution B was dosed over a period of 90minutes using varying addition rates as described in the table below.Solution C was dosed at a constant speed of 4.0 g/h over a period of 90min followed by a higher dosing speed of 40 g/h over an additional 37minutes. During the 90 minute dosing period of solution B, the pH in thereactor was maintained at 6.5 by adding 20% aqueous NaOH solution. A pHof 6.6 was measured for the polymer solution after the addition ofsolution C was complete. An aqueous solution of a polyether-polyestercopolymer with a yield of 94.7%, a weight-average molecular weight of32,700 g/mole, a PDI of 2.13 as determined by SEC and a solids contentof 38.6% was obtained.

Ramp Table J t (min) 0 9 18 27 36 45 54 63 72 81 90 g/h 246 280 295 280244 185 127 85 59 49 0

Examples 25-28 and Comparative Example 29

Sample cementitious compositions were prepared by first introducing theadmixtures and defoamer into the mix water in the amounts listed inTable 7 below. The stone, cement and sand were added in the amountsshown in Table 7, and the mixture was mixed for five minutes at 20 rpmin a drum mixer. The slump of a sample of this mixture was tested (testduration approximately two minutes), and mixing resumed within fiveminutes, at four rpm. Mixing cycles of 20 minutes followed by testcycles of five minutes were repeated to generate the data shown in Table7. All of the sample cementitious compositions included a conventionalpolycarboxylate ether dispersant in the amounts shown in Table 7. Thesample cementitious compositions of Examples 25 through 28 also includedthe following non-ionic copolymers, respectively: Copolymer B describedabove, Copolymer H having Component A hydroxypropylacrylate residues andComponent C polyethylene glycol vinyl ether residues in a molar ratio of4:1, Copolymer A described above, and Copolymer J having Component Ahydroxypropylacrylate residues and Component B polyethylene glycol vinylether residues in a molar ratio of 4:1.

The workability of each cementitious composition, as represented by itsslump, was determined according to ASTM C143, reported in Table 7,below. The air content, set time (ASTM C403), and compressive strength(ASTM C39) of each composition were also determined, reported in Table7. As shown in Table 7 and FIG. 8, the subject copolymers as describedherein, when combined with conventional polycarboxylate etherdispersants, extend the workability of the composition much moreeffectively than the conventional polycarboxylate ether dispersantalone, regardless of whether the hydroxyethylacrylate orhydroxypropylacrylate moiety was present (although apparentlyhydrolyzing at differing rates), while increasing the compressivestrength of the final product and not significantly changing set timeand air content.

TABLE 7 Ex. 25 Ex. 26 Ex. 27 Ex. 28 Comp. Ex. 29 Dose (% cmt) 0.0040.004 0.004 0.004 0.004 Defoamer TBP TBP TBP TBP TBP Dose (% cmt) 0.10.1 0.1 0.1 0.115 Admixture PCE PCE PCE PCE PCE Dose (% cmt) 0.1 0.1 0.10.1 Admixture Copolymer B Copolymer H Copolymer A Copolymer J Cement(lbs/yd3) 567 547 567 547 561 Sand (lbs/yd3) 1430 1379 1431 1381 1415Stone 1 (lbs/yd3) 1847 1782 1849 1784 1829 Water (lbs/yd3) 271 262 272262 269 Water/Cement 0.48 0.48 0.48 0.48 0.48 Sand/Aggregate 0.45 0.450.45 0.45 0.45 Slump (in)  5 Min 9.50 9.50 9.50 9.50 9.75 30 Min 9.258.50 9.75 7.75 6.00 55 Min 8.75 7.75 8.25 6.00 2.75 80 Min 7.00 6.005.50 3.25 2.00 Total Slump Loss 2.50 3.50 4.00 6.25 7.75 Air Content (%) 5 Min 1.5 5.0 1.4 4.9 2.5 80 Min 2.2 2.5 1.8 2.1 2.3 Gravametric Air(%) Initial 2.7 5.6 1.4 5.3 2.7 Initial Set (hrs) 4.8 4.6 4.8 4.7 4.3Final Set (hrs) 6.1 5.9 6.0 5.8 5.7 Compressive Strengths (psi)  1 Day2730 2740 2860 2680 2510  7 Day 5440 5630 5850 5570 5310 28 Day 67806780 7060 6830 6480

Examples 30 and 31 and Comparative Example 32

Sample cementitious compositions suitable for use in pre-castapplications were prepared by first introducing the admixtures anddefoamer into the mix water in the amounts listed in Table 8 below. Thestone, cement and sand were added in the amounts shown in Table 8, andthe mixture was mixed for five minutes at 20 rpm in a drum mixer. Theslump of a sample of this mixture was tested (test durationapproximately two minutes), and mixing resumed within five minutes, atfour rpm. Mixing cycles of 20 minutes followed by test cycles of fiveminutes were repeated to generate the data shown in Table 5. Examples 30and 31 included differing ratios of a combination of Copolymer Bdescribed above, and a conventional polycarboxylate ether dispersant,while Comparative Example 32 included only a conventionalpolycarboxylate ether dispersant.

The workability of each cementitious composition, as represented by itsslump, was determined according to ASTM C143, reported in Table 8,below. The air content, set time (ASTM C403), and compressive strength(ASTM C39) of each composition were also determined and are reported inTable 8. As shown in Table 8 and FIG. 9, a combination of Copolymer Band a conventional polycarboxylate ether dispersant, as used in Examples30 and 31, maintain the workability of the cementitious compositionslonger than the polycarboxylate ether (PCE) utilized in ComparativeExample 20, while not sacrificing air content or set time, andincreasing the compressive strength. Further, as shown by the increasedworkability of Example 31 compared with Example 30, an increased amountof Copolymer B performed better than a lesser amount of Copolymer B.

TABLE 8 Ex. 30 Ex. 31 Comp. Ex. 32 Dose (% cmt) 0.003 0.003 0.003Defoamer TBP TBP TBP Dose (% cmt) 0.054 0.080 — Admixture Copolymer BCopolymer B — Dose (% cmt) 0.106 0.106 0.106 Admixture PCE PCE PCECement (lbs/yd3) 601 601 600 Sand (lbs/yd3) 1370 1370 1367 Stone 1(lbs/yd3) 1877 1877 1874 Water (lbs/yd3) 271 271 270 Water/Cement 0.450.45 0.45 Sand/Aggregate 0.44 0.44 0.44 Slump (in)  5 Min 8.75 8.25 8.0030 Min 8.25 8.25 5.00 55 Min 6.50 8.50 3.00 80 Min 4.75 6.75 2.00 AirContent (%)  5 Min 1.8 1.8 2.0 80 Min 2.1 2.2 2.1 Initial Set (hrs) 4.24.4 4.3 Final Set (hrs) 5.5 5.7 5.6 Compressive Strengths (psi)  1 Day2950 3160 2640  7 Day 5770 6400 5350 28 Day 7230 7890 6520

Examples 33, 34 and 35, and Comparative Example 36

Three additional copolymers were prepared having a ratio ofhydroxyethylacrylate residues to polyethylene glycol vinyl etherresidues of 4:1. Copolymer K and Copolymer L had a molar ratio ofComponent B polyethylene glycol vinyl ether residues (molecular weight1100) to Component C polyethylene glycol vinyl ether residues (molecularweight 3000) of 0.5/0.5. Copolymer M had a molar ratio of Component Bpolyethylene glycol vinyl ether residues (molecular weight 1100) toComponent C polyethylene glycol vinyl ether residues (molecular weight3000) of 0.7/0.3.

Sample cementitious compositions were prepared by introducing theadmixtures and defoamer into the mix water in the amounts listed inTable 9 below. The stone, cement and sand were added in the amountsshown in Table 9, and the mixture was mixed for five minutes at 20 rpmin a drum mixer. The slump of a sample of this mixture was tested (testduration approximately two minutes), and mixing resumed within fiveminutes, at four rpm. Mixing cycles of 20 minutes followed by testcycles of five minutes were repeated to generate the data shown in Table9. All of the sample cementitious compositions included a conventionalpolycarboxylate ether dispersant in the amounts shown in Table 9. Thesample cementitious compositions of Examples 33 through 35 also includedthe following copolymers, respectively: Copolymer K, Copolymer L andCopolymer M, as described above.

The workability of each cementitious composition, as represented by itsslump, was determined according to ASTM C143, reported in Table 9,below. The air content, set time (ASTM C403), and compressive strength(ASTM C39) of each composition were also determined, reported in Table9. As shown in Table 9 and FIG. 10, the subject copolymers as describedherein, when combined with conventional polycarboxylate etherdispersants, extend the workability of the composition much moreeffectively than the conventional polycarboxylate ether dispersantalone, while increasing the compressive strength of the final productand not significantly changing set time and air content.

TABLE 9 Ex. 33 Ex. 34 Ex. 35 Comp. Ex. 36 Dose (% cmt) 0.004 0.004 0.0040.004 Defoamer TBP TBP TBP TBP Dose (% cmt) 0.10 0.10 0.10 — AdmixtureCopolymer K Copolymer L Copolymer M — Dose (% cmt) 0.10 0.10 0.10 0.12Admixture PCE PCE PCE PCE Cement (lbs/yd3) 570 570 568 568 Sand(lbs/yd3) 1433 1433 1428 1428 Stone 1 (lbs/yd3) 1868 1868 1862 1862Water (lbs/yd3) 258 258 258 258 Water/Cement 0.45 0.45 0.45 0.45Sand/Aggregate 0.45 0.45 0.45 0.45 Slump (in)  5 Min 8.50 9.00 9.00 9.5030 Min 8.75 8.25 7.25 5.50 55 Min 8.00 6.00 8.00 2.50 80 Min 4.50 4.007.25 2.00 Air Content (%)  5 Min 1.8 1.8 2.1 2.1 80 Min 2.1 2.4 1.8 2.3Initial Set (hrs) 4.3 4.6 4.7 4.4 Final Set (hrs) 5.5 5.8 6.0 5.8Compressive Strengths (psi)  1 Day 3380 3440 3330 2830  7 Day 6360 63506430 5640 28 Day 7880 8000 7750 6930

The subject non-ionic copolymer, although having no initial affinity forcement particles, in combination with cementitious compositions exhibitssuperior workability retention, minimizes the need for slump adjustmentduring production and at the jobsite, minimizes mixture over-designrequirements, reduces re-dosing of high-range water-reducers at thejobsite, and provides high flowability and increased stability anddurability. The subject copolymer admixture system is suitable forextending workability of cementitious compositions adapted for readymix, highly-filled, precast, and other applications, such as oil wellgrouts.

It will be understood that the embodiments described herein are merelyexemplary, and that one skilled in the art may make variations andmodifications without departing from the spirit and scope of theinvention. All such variations and modifications are intended to beincluded within the scope of the invention as described hereinabove.Further, all embodiments disclosed are not necessarily in thealternative, as various embodiments of the invention may be combined toprovide the desired result.

1. A process for the preparation of a non-ionic copolymer comprising atleast one hydrolysable monomer residue and at least one polyethermacromonomer residue in a semicontinuous mode of operation in apolymerization apparatus containing a polymerization reactor associatedwith a metering device, the process comprising: introducing at least aportion of the polyether macromonomer with low reactivity and water intothe polymerization reactor, wherein the hydrolysable monomer with higherreactivity which is added thereto forms an aqueous medium polymerizationreaction mixture, optionally wherein the aqueous medium is present inthe form of an aqueous solution; introducing at least a portion of thehydrolysable monomer into the metering device; adding at least a portionof the hydrolysable monomer into the polymerization reactor from themetering device; passing a free radical polymerization initiator intothe polymerization reactor before and/or during the addition of thehydrolysable monomer into the polymerization reactor, wherein thehydrolysable monomer and the polyether macromonomer are reacted in theaqueous medium polymerization reaction mixture by free radicalpolymerization with formation of the non-ionic copolymer; and,subjecting the reaction mixture to polymerization while an addition rateof the hydrolysable monomer and/or at least a component of the freeradical polymerization initiator is varied stepwise or continuously;wherein no monomer is introduced into the polymerization reactor toincorporate ionic cement binding sites into the non-ionic copolymerprior to mixing the copolymer in an alkaline aqueous environment.
 2. Theprocess of claim 1, wherein at least 70 mol % of the polyethermacromonomer initially introduced into the polymerization reactor isconverted by the free radical polymerization.
 3. The process of claim 1,wherein the hydrolysable monomer is at least one ethylenicallyunsaturated hydrolysable monomer of Component A and the polyethermacromonomer is at least one ethylenically unsaturated polyoxyalkyleneether-based monomer of Component B and/or Component C.
 4. The process ofclaim 3, wherein the polymerization reaction mixture contains a portionof the monomer of Component B and/or Component C together with at leasta portion of Component A before polymerization is commenced.
 5. Theprocess of claim 3, comprising initially adding the ethylenicallyunsaturated monomer of Component B and/or Component C in advance intothe reactor in their whole amount before the addition into the reactorof any of the ethylenically unsaturated monomer of Component A.
 6. Theprocess of claim 3, further comprising introducing into thepolymerization reactor at least one further unsaturated monomer ofComponent D.
 7. The process of claim 1, wherein a redox initiator systemis used as the free radical polymerization initiator.
 8. The process ofclaim 7, wherein the redox initiator system is the combinationH₂O₂/FeSO₄ together with a reducing agent.
 9. The process of claim 8,wherein the reducing agent comprises disodium salt of2-hydroxy-2-sulphinatoacetic acid, the disodium salt of2-hydroxy-2-sulphonatoacetic acid, sodium hydroxymethanesulphinate,ascorbic acid, isoascorbic acid, or mixtures thereof.
 10. The process ofclaim 7, wherein a component of the redox initiator system/reducingagent, and optionally a chain transfer agent, are passed into thepolymerization reactor after a polymerization pH has been established.11. The process of claim 7, wherein a component of the redox initiatorsystem/reducing agent, and optionally a chain transfer agent, are passedinto the polymerization reactor after a polymerization pH has beenestablished, and while the hydrolysable monomer is metered in.
 12. Theprocess of claim 1, wherein 80 mol % to at least 90 mol %, of thepolyether macromonomer initially introduced into the polymerizationreactor is converted by the free radical polymerization.
 13. The processof claim 1, wherein a polymerization pH is established at about 4.5 toabout 7.1, and the temperature of the aqueous medium during the freeradical polymerization is 0 to about 90° C., optionally about 10 toabout 35° C.
 14. The process of claim 1, wherein the hydrolysablemonomer is initially introduced together with water into the meteringdevice and an aqueous solution of the hydrolysable monomer is added fromthe metering device into the polymerization reactor.
 15. The process ofclaim 1, wherein a chain regulator, which is optionally in dissolvedform, is passed into the polymerization reactor.
 16. The process ofclaim 1, wherein the polyether macromonomer is initially introduced intothe polymerization reactor in an amount per mole of hydrolysable monomeradded and/or metered in such that an arithmetic mean molar ratio ofhydrolysable monomer residues to polyether macromonomer residues ofabout 10:1 to about 1:1 is established in the non-ionic copolymerformed.
 17. The process of claim 1, wherein the polyether macromonomeris initially introduced into the polymerization reactor in an amount permole of hydrolysable monomer added and/or metered in such that anarithmetic mean molar ratio of hydrolysable monomer residues topolyether macromonomer residues of about 9:1 to about 1:1 is establishedin the non-ionic copolymer formed.
 18. The process of claim 1, includingpassing a chain transfer agent into the polymerization reactor beforeand/or during the addition of the hydrolysable monomer into thepolymerization reactor.
 19. The process of claim 1, wherein thepolymerization reactor is present as a semicontinuously stirred tank.